Structure having flush circuitry features and method of making

Abstract

Embedded flush circuitry features are provided by providing a carrier foil having an electrically conductive layer therein and coating the electrically conductive layer with a dielectric material. Circuitry features are formed in the dielectric material and conductive metal is plated to fill the circuitry features.

What is claimed is:  
     
       1. A structure having first and second major surfaces comprising: 
       a carrier foil forming a first said major surface;  
       an electrically conductive layer on one of the major surfaces of the carrier foil;  
       a dielectric layer located on the electrically conductive layer wherein the dielectric layer having circuitry features; and  
       plated metal conductive circuitry located within the circuitry features wherein the metal conductive circuitry is substantially flush/coplanar with and surrounded by the dielectric layer, wherein said flush metal conductive circuitry forms interconnects from any via in the structure to any other via in the structure; and  
       wherein said metal/dielectric co-plane forms said second major surface.  
     
     
       2. The structure of  claim 1  wherein the circuitry features in the dielectric layer are formed completely thru it to the conductive layer. 
     
     
       3. The structure of  claim 1  wherein the circuitry features in the dielectric layer are formed short of the conductive layer. 
     
     
       4. The structure of  claim 1  wherein the conductive circuitry comprised lines of about 0.5 to about 1 mil wide and being about 0.5 to about 3 mils spaced apart. 
     
     
       5. The structure of  claim 1  wherein the metal conductive circuitry comprise copper. 
     
     
       6. The structure of  claim 1  wherein the dielectric layer comprises an epoxy resin or polyimide resin. 
     
     
       7. The structure of  claim 1  wherein the carrier foil comprises copper. 
     
     
       8. The structure of  claim 1  wherein the electrically conductive layer comprises chromium. 
     
     
       9. The structure of  claim 1  wherein the flush metal conductive circuitry is covered with gold or nickel-gold. 
     
     
       10. The structure of  claim 1  wherein a cavity exist thin the dielectric layer to the electrically conductive layer wherein said cavity resides an electronic component. 
     
     
       11. The structure of  claim 1  wherein the structure is attached to a stiffening dielectric layer. 
     
     
       12. The structure of  claim 1  wherein the flush metal conductive circuitry is selectively covered with gold or nickel-gold. 
     
     
       13. The structure of  claim 12  wherein gold wire bond attach exist between gold covered circuitry and other components or circuitry features attached to the structure. 
     
     
       14. A structure comprising repetitive layers of a structure of  claim 1  attached together by a dielectric layer. 
     
     
       15. The structure of  claim 14  comprising interconnects from any layer of a conductive metal circuitry to any other layer of conductive metal circuitry. 
     
     
       16. A structure, having first and second external major surfaces, comprising: 
       a stiffening dielectric base layer having first and second buried major surfaces;  
       a first circuitry layer located on said first buried major surface;  
       a second circuitry layer located on said second buried major surface;  
       each said circuitry layer further comprising:  
       a layer of a patterned dielectric material having circuitry features defined therein;  
       and plated metal conductive circuitry located within the circuitry features wherein the metal conductive circuitry is substantially flush/coplanar with and surrounded by said patterned dielectric layer, wherein said flush metal conductive circuitry forms interconnects from any via in the structure to any other via in the structure; and wherein said metal circuitry/dielectric co-plane form at least one of said external major surfaces.  
     
     
       17. A structure comprising repetitive layers of the structure of  claim 16  wherein the conductive circuitry comprises lines of about 0.5 to about 1 mil wide and being about 0.5 to about 3 mils spaced apart and wherein said stiffening dielectric base layers are attached together by a circuitry layer. 
     
     
       18. The structure of  claim 16  wherein the metal conductive circuitry comprises copper. 
     
     
       19. The structure of  claim 16  wherein the dielectric circuitry containing layer comprises an epoxy resin, polyimide resin or photoimageable dielectric. 
     
     
       20. The structure of  claim 16  wherein the dielectric base layer comprises an epoxy resin, polyimide resin or photoimageable dielectric. 
     
     
       21. The structure of  claim 16  wherein a cavity exist thru the dielectric layer to the metal conductive layer wherein said cavity resides an electronic component. 
     
     
       22. The structure of  claim 16  wherein the structure is attacked to a stiffening dielectric layer. 
     
     
       23. The structure of  claim 16  wherein the flushmetal conductive circuitry is covered with gold or nickel-gold. 
     
     
       24. The structure of  claim 23  wherein gold wire bond attach exist between gold covered circuitry and other components or circuitry features attached to the structure. 
     
     
       25. A structure comprising repetitive layers of the structure in  claim 16  attached together by a dielectric layer. 
     
     
       26. The structure of  claim 25  comprising interconnects from any layer of conductive metal circuitry to any other layer of conductive metal circuitry. 
     
     
       27. A structure comprising a dielectric base layer; a second dielectric layer containing circuitry features located upon the base dielectric layer; and metal conductive circuitry located within the circuitry features wherein the metal conductive circuitry is substantially flush/coplanar with and surrounded by the second dielectric layer; 
       wherein the conductive circuitry comprises lines of about 0.5 to about 1 mil wide and being about 0.5 to about 3 mils spaced apart and circuit features of sufficient size to permit an electronic component to be located in said structure, wherein said flush metal conductive circuitry forms interconnects from any via in the structure to any other via in the structure.  
     
     
       28. The structure of  claim 27  wherein said electronic component is an integrated circuit chip and wherein a cavity exists thru the dielectric layer to the metal conductive layer and wherein said integrated circuit chip resides in said cavity. 
     
     
       29. The structure  claim 28  wherein the flush metal conductive circuitry is covered with gold or nickel-gold, and 
       wherein gold wire bond attach exists between gold covered circuitry and said integrated circuit chip.